How to design a form for accessibility using ARIA?

I’m redesigning an application form and want to make sure it is as accessible as possible. I’m not an expert in accessibility by any means, but I am trying to mark up the design for developers to code. Am I using the labels correctly?

  1. Should the box for role="form" aria-label="primary contact" include the Primary Contact and description sentence, or just the entry fields?
  2. The Designated Signee question is dynamic. Selecting Same as Primary Contact results in the fields below being hidden. What is the correct naming convention for the radio group and what should the orange box cover?
  3. Any tips for what I should label the headings "Primary Contact" and "Designated Signee" to make it easier for the developers? Do they need id="xxx" tags?

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